Chapters 12 and 13 We have skipped chapters
- Slides: 70
Chapters 12 and 13 We have skipped chapters 12 and 13 that go through Van der Waals type equations of state (the d (del) solubility parameter)and group contribution methods where we consider chemical groups for each mixture molecule and add up their contribution to miscibility through a term like the d -solubility parameter. We don’t have time to go through chapters 12 and 13, though you may find them useful and interesting to read in the future. At this point we need to recognize the names of different models and be able to use the equations and approaches to estimate solubility and separation problems. The specific functions you will most use will be limited to one equation for specific fields for instance, the Flory-Huggins equation for polymers and UNIFAC for petrochemicals. So you don’t really need to know all of the equations. Generally being able to pickup the different equations and apply them to problems is of use and we will do that in Chapter 14. 1
2
3
4
5
6
7
8
9
Important to stripping, liquid extraction, precipitation and other separation processes. 10
11
12
13
Calculate gamma using 12. 36 And zero limit For pure x = 1 y=1 so Py = x Psat gamma P = Psat and gamma is 1 for pure So (x gamma) for matching phase with pure is 1 so get x then use x and 12. 36 To get gamma, then get x from 1/gamma 14
15
16
17
18
19
20
Activity aiα =aiβ 21
Activity aiα =aiβ For ternary x 3 given 22
USE UNIFAC, MAB, SSCED etc. 23
24
25
26
27
28
Gibbs phase rule F = C – P +2 F =1 = line F = 0 = point F = 2 = space 29
Continuous Batch 30
Each plot is for a fixed T and P 31
32
A 12 = a + b/T 33
34
35
36
37
38
39
40
41
42
SSCED p. 482 43
Ice/salt melting point depression 44
45
UNIFAC. xls 46
47
48
49
50
51
52
53
54
See Wax. xlsx 55
56
pp 14. 3 a’s are Van der Waals constants 57
58
59
60
61
62
63
64
65
66
67
68
69
70